How Banks Work: Profit, Fees, and Your Money

Banks Are Businesses, Not Vaults

Most people think of banks as safe places to store money. While that is true, it misses the bigger picture. Banks are profit-seeking businesses, and understanding how they make money is essential to protecting yours.

When you deposit R$5,000 into your conta corrente (checking account), the bank does not lock that money in a vault with your name on it. Instead, it lends most of that money to other customers — people taking out car loans, families financing homes, businesses funding expansion. The bank pays you little or nothing for using your money, then charges borrowers significantly more. That difference is called the spread bancario, and it is the engine of banking profit.

Brazil has historically had one of the highest banking spreads in the world. While the Selic rate might be around 10-13%, credit card revolving interest (rotativo) can exceed 400% per year. This enormous gap between what banks pay depositors and what they charge borrowers is a defining feature of the Brazilian financial system, and one reason why understanding banking fees and alternatives is so important.

The Fractional Reserve System

Banks are required to keep only a fraction of deposits on hand — the rest is lent out. In Brazil, the Banco Central sets compulsory deposit requirements (depositos compulsorios) that determine how much banks must keep in reserve. These requirements vary by deposit type:

• Demand deposits (conta corrente): Banks must keep a significant percentage with the Banco Central
• Savings deposits (poupanca): A portion must be directed to housing finance (SFH)
• Time deposits (CDB): Lower reserve requirements apply

This system works because not all depositors withdraw money at the same time. Your R$5,000 deposit might support R$4,000 or more in new loans. Those borrowers spend the money, which gets deposited in other accounts, creating even more lending capacity. This multiplication effect is how the banking system creates money beyond what the Banco Central physically prints.

How the Selic Rate Shapes Everything

The Selic rate is the foundation of all interest rates in Brazil. Think of it as the wholesale price of money. When the COPOM raises the Selic:

• Borrowing becomes more expensive. Banks raise rates on loans, credit cards, and financing
• Saving becomes more rewarding. CDBs, Tesouro Selic, and other fixed-income products pay more
• Spending slows down. Higher borrowing costs discourage consumption, which helps cool inflation

When the COPOM lowers the Selic, the opposite happens. This is why the Selic rate decisions are front-page news in Brazil — they affect everything from your mortgage payment to the return on your savings options.

How Banks Earn Revenue

Beyond the spread, Brazilian banks generate revenue through several channels:

Interest Income

This is the largest revenue source. Banks earn interest on:

• Personal loans (emprestimo pessoal)
• Payroll-deducted loans (consignado)
• Auto financing
• Mortgage loans
• Credit card revolving balances and installment plans
• Corporate lending

The difference between what they pay you (often zero on a conta corrente) and what they charge borrowers (potentially hundreds of percent on credit cards) is pure margin.

Fee Income (Tarifas)

Brazilian banks charge fees for a wide range of services. Common fees include:

• Conta corrente maintenance: Monthly account fees, though many banks now offer free options
• TED/DOC transfers: Wire transfer fees (increasingly replaced by free PIX)
• Card annuity (anuidade): Annual credit card fees ranging from R$0 to R$800+
• Statement printing: Fees for paper statements
• Overdraft (cheque especial): One of the most expensive credit lines in Brazil, though now capped by regulation
• Package fees (pacote de servicos): Bundled service packages

The Banco Central requires banks to offer a standardized set of essential services for free (servicos essenciais), including a basic debit card, up to four withdrawals per month, and monthly statements. Beyond this, banks create tiered service packages with increasing fees.

Investment Product Commissions

Banks earn commissions when they sell you investment funds, insurance policies, capitalizacao titles (a lottery-like savings product that generally benefits only the bank), and previdencia privada plans. This creates a conflict of interest — the products the bank pushes hardest are often the ones that pay the bank the most, not the ones best for you.

Understanding the CET

The Custo Efetivo Total (CET) is one of the most important numbers in Brazilian consumer finance. It represents the true total cost of a loan or credit product, expressed as an annual percentage. Unlike the nominal interest rate, the CET includes:

• The base interest rate
• IOF tax (Imposto sobre Operacoes Financeiras)
• Insurance premiums (often bundled into loans)
• Administrative fees
• Registration fees

By law, every financial institution must disclose the CET before you sign a loan contract. Always compare loans by their CET, not by the advertised interest rate. A loan advertising “1.5% per month” might have a CET of 25% or more once all costs are included.

The Cheque Especial Trap

The cheque especial (overdraft facility) deserves special attention because it has historically been one of the most expensive credit products in the world. If your conta corrente balance drops below zero, the cheque especial automatically kicks in, lending you money at rates that were historically above 300% per year.

In 2020, the Banco Central capped cheque especial interest at 8% per month for balances up to R$500, but rates above that threshold can still be punishing. The key danger is that the cheque especial activates automatically — you might not even realize you are borrowing at extreme rates until you check your statement.

Practical rule: Treat the cheque especial as if it does not exist. If your account approaches zero, transfer money from savings or cut spending immediately rather than dipping into this facility. If you find yourself using it regularly, that is a sign you need to revisit your budget.

Bank Concentration in Brazil

Brazil’s banking sector is highly concentrated. The five largest banks — Banco do Brasil, Itau Unibanco, Bradesco, Caixa Economica Federal, and Santander — hold the vast majority of total banking assets. This concentration has historically limited competition and kept fees and spreads high.

However, the landscape is changing rapidly. The Banco Central has actively promoted competition through:

• PIX: A free, instant payment system that eliminated banks’ fee revenue from transfers
• Open Finance: A framework that lets you share your financial data across institutions, making it easier to switch banks and find better products
• Simplified licensing: Making it easier for digital banks and fintechs to enter the market

The rise of neobanks like Nubank, Inter, and C6 Bank has forced traditional banks to reduce fees and improve their digital offerings. This competition directly benefits you as a consumer.

How to Evaluate Your Bank

When choosing or evaluating a bank, consider these factors:

Fees and costs. Add up every monthly fee you pay — account maintenance, card annuity, transfer fees, package fees. Many Brazilians pay R$50-100 per month in bank fees without realizing it. Digital banks often charge R$0 for these same services.

Interest rates on credit. If you use credit products, compare the CET across institutions. The difference between banks on the same loan type can be significant.

Investment options. Many traditional banks steer customers toward their own high-fee investment funds. Independent brokers and digital platforms often offer better returns with lower costs.

Digital experience. How good is the app? Can you do everything you need without visiting a branch? In 2026, there is no reason to tolerate a clunky banking app.

Customer service. Check complaint rankings on the Banco Central’s website. Some banks consistently rank worse for customer service and dispute resolution.

Security. Ensure the bank is authorized by the Banco Central and covered by the FGC (Fundo Garantidor de Creditos). Verify mobile banking security practices before trusting any institution with your money.

Key Takeaways

• Banks are businesses that profit primarily from the spread between deposit rates and lending rates. Brazil’s spread is among the highest in the world.
• The fractional reserve system means banks lend out most of your deposits, keeping only a fraction in reserve as required by the Banco Central.
• The Selic rate set by the COPOM influences every interest rate in the economy — from your savings returns to your loan costs.
• Always compare financial products using the CET, not the advertised interest rate.
• Avoid the cheque especial at all costs — it is one of the most expensive credit lines available.
• Bank concentration in Brazil is decreasing thanks to PIX, Open Finance, and neobank competition.
• Evaluate banks on total fees, interest rates, investment options, digital experience, and FGC coverage.

In the previous lesson, you learned what money is and how inflation works. In the next lesson, you will explore the full architecture of Brazil’s financial system and the institutions that regulate and protect your money.